Automatic switching mechanism



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A WULLSCHLEGER auwomnc swmcaxue MECHANISM Filed March 5, 1931 INVENTORBY 1W ATTORNEY Aug. 22, 1933.

Patented Aug. 22, 1 933 1,923,902 AUTOMATIC SWITCHING MECHANISM AlbertWullschleger, Zng, Switzerland, assignor to Landis & Gyr, A. (1., Zug,Switzerland, a (301'- poration of Switzerland Applieation March 5, 1531,Serial No. 520,317, and in Switzerlandlllarch 13, 1930 10 Claims. (Cl.l"!375) The present invention relates to automatic switching mechanismand more particularly to an automatic motor-actuated switching mechanismadapted to be controlled by temperature or 5 other changes.

Objects and advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be learned bypractice with the invention, the same being realized and attained bymeans of the instrumentalities i 26 of the invention.

Of the drawing: Fig. 1 is a diagrammatic view illustrating thecontrolling circuit for the automatic switching mechanism; and

Fig. 2 is a diagrammatic view illustrating the present preferred andillustrative embodiment of the invention.

The present invention has for its object the provisionof an automaticswitching mechanism in which the relays controlling the switchingoperations remain energized only for a very short period of time,thereby reducing the danger of overloading the relays. A further objectis the provision of an automatic switching mechanism 35 in which therelays are operative only during the beginning of the switching period.Still another object of the invention isthe provision of a switchingmechanism in which each switching op eration automatically sets themechanism in re verse switching position ready to operate as soon as thecontrolling conditions change in a predetermined manner.

- Figure 1 of the drawing illustrates diagrammatically the principalcircuits employed in the 45 present preferred and illustrativeembodiment of the invention, and, as there shown, a motor 9 is providedto actuate the switching mechanism for the main circuit. The motorcontrolling circuit comprises the conductor 10, leading from one side 50of the main 11, to the motor 9, and'thence to a double throw switch arm12 which can be moved to contact with either of the contacts 13 or 14.

Contacts 13 and 14 are connected by conductors 20 and 21 with othercontacts 15 and 16 respectively which cooperate with a second doubleloosely mounted stop arm 46 which contacts with throw switch arm 17 toconnect the switch with the main 18 through conductor 19.

Motor 9 is mechanically connected with the switching arm 12 to move thearm from one of the contacts 13 or 14 to the other each time the motoris energized, and other electromagnetic motive means 22 is provided tosimilarly move theswitch arm 17 between its contacts 15 and 16.

For controlling the circuits previously described and causing aswitching operation at predetermined times and-upon predeterminedchanges in' temperature, a temperature responsive switching mechanism isprovided. This comprises the temperature controlled switching'arm 23which contacts with either of its contacts 24 or 25. Con tact 24 isconnected with contacts 13 and 15, and contact .25 is connected withcontacts 14 and 16, while the switching arm 23 is connected with onecontact 26 oi. a double-throw time switch 28. The switch arm 29 of thetime switch 28 is connected with themotive means 22 through conductor 30and the other contact 31 of switch 28 is'connected withconductor 20. v

Figure 2 of the drawing shows the circuits more in detail together withthe mechanical parts cause ing the successive operations to be performedin accordance with the changes in temperature or with time. As embodied,the main switch 34, which is to be controlled by the remainder of themechanism, comprises stationary contacts 35, and 85 movable contacts 36which are connected in the circuit of the mechanism or heater to becontrolled in the usual manner. The contacts 36 .are normally held incontact with the stationary contacts by the resiliency of the springsupports 37 carrying the movable contacts, and-contacts 36 are moved tocircuit breaking position out of contact with contacts 35 by movement ofthe insulated bar 38 supported on pivoted bell cranks 39.

Switch 34 is opened and closed by means of a small motor 9, which isconnected to crank through reduction gearing, and crank 40 is connectedwith bell-crank 39 by pitman 41. For insuring quick opening and closingof switch 34, crank 40 is supported on shaft 42 on which is rotatablegear 43 of the reduction gearing. Shaft 42 also carries an eccentric 44loosely mounted thereon, the eccentric being fastwith respect to theswitch-actuating shoe 45 and carrying the stops 47 and 48, and abutsagainst pin 45' mounted on shoe 45. Shoe 45 and crank 40 areconnectedwith gear 43 by means of the spiral spring 49, so that as gear 43rotates, eccentric 44 is rotated until stop arm 46 is withdrawn fromcontact .with 1' 49 to rotate the crank and shoe until stop arm 46 comesin contact with the other stop. This half-revolution of crank 40 opensor closes switch 34.

Shoe 45 moves arm 12 of switch 12 into contact with contact 13 andpermits it to be resiliently moved into engagement with contact 14 onalternate half-revolutions of the shoe.

In this embodiment, the electromagnetic mo tive means 22, for the switch17' comprises a toothed wheel 50 rotatably mounted and fast with respectto a ratchet wheel 51, held against retrograde movement by means of dog52, and moved by means of the pawl 53 which is drawn forwardly byoscillation of the movable armature 54 each time electromagnet 55 isenergized. Toothed wheel 50 is positioned with respect to the switch 1'7that the teeth lift arm 1'? into contact with contact 16, and on asingle actuation of the armature 54, the arm resiliently moves intocontact with the contact 15.

The temperature responsive means preferably comprises a bimetallicmember 23 forming the movable switch arm and supported between thecontacts 24 and 25 so that on being heated beyond a predeterminedtemperature it moves to close the circuit through contact 24, and oncooling below a predetermined temperature moves to close the circuitthrough. contact 25.

p The time controlled means preferably comprises a clock driven discwhich rotates in accordance with time, and carries a plurality of switchactuating pins 61 which alternately close and'open the switch 29'. Asembodied, there is provided a rotatable cam 62 having alternate high andlow surfaces which cooperate with the switch arm 29 to alternately closeand open the switch, and this cam is rotatably mounted by means of shaft64 which also carries a star wheel 65 adapted to be moved a quarterrevolution each time it comes in engagement with a pin 61. A spring 66is provided cooperating with the squared mem ber 67 mounted on the shaftfor holding the cam and star wheel in one of their four positions.

As shown in this figure, the parts are connected in circuit the same asin Figure 1, contacts 13, 15, 24 and 31 being connected together, as arecontacts 14, 16 and 25. Contact 26 is connected with switch arm 23, andthe electromagnetic motive means is connected between switch arm 29 andmain 11.

Figure 2 shows the parts in the position they assumed after the mainswitch 34 was opened by an increase in temperature beyond thepredetermined limit. I

As the temperature falls, bimetal strip 23 contacts with contact 25 toclose this switch, establishing a circuit, as follows: from main 11,

through the coil of magnet 22, through arm 29, contact 26, bimetal strip23, contact 25, contact 16, arm 17 and through conductor 19 to main 18.This energizes the electrornotive means 22,

causing arm 17 to contact with contact 15, which closes the circuit toenergize motor 9 which continues to rotate until switch 34 is closed andarm 12 is simultaneously moved to contact with contact 14, interruptingthe motor circuit.

In case the time switch moves arm '29 next, this arm contacts withcontact 31, the electromagnet 22 is energized, which moves arm 17 tocontact with contact 16, thereby energizing motor 9 and causing switch34 to be opened.

If the temperature rose beyond the predetermined'limit before the timeswitch opened the circuit, the magnet 22 would be actuated by contact ofarm 23 and contact 24, which would shift arm 1'7 to contact with contact16 thereby 'limited'to the specific mechanisms shown and described butdepartures may be made therefrom within the scope of the accompanyingclaims without departing from the principles of the invention andwithout sacrificing its chief advantages.

What I claim is:

1. Automatic switching mechanism including in combination a main switchand motive means for opening and closing the switch, a'temperatureresponsive switch controlling the supply of energy to the motive means,and means set in operation by the temperature responsive switch forinterrupting the flow of current through said temperature responsiveswitch while continuing the supply of energy to the motive means untilthe main switch has been fully operated.

2. Automatic switching mechanism including in combination a main switchand motive means for opening and closing the switch, a periodicallyactuated switch controlling the supply of energy to the motive means,and means set in operation by the periodically actuated switch forinterrupting the flow of current through said periodically actuatedswitch while continuing the supply of energy to the motive means untilthe main switch has been fully operated. I

3. Automatic switching mechanism including in combination a main switchand motive means for opening and closing said switch,'means forsupplying energy to said motive means to complete the switchingoperation once it is initiated, a controlling means for supplying energyto the motive means and means for interrupting the supply of energythrough the controlling means immediately after the motive means arestarted without interrupting the supply of energy tothe motive means andmeans for thereafter interrupting the supply of energy to the motivemeans on completion of the switching operation.

4. Automatic switching mechanism including in combination a main switchand motive means for opening and closing said switch, means forintermittently supplying the motive means with energy, means forthereafter interrupting the flow of current through the second means andfor interrupting the supply of energy to'the motive means as soon as itcompletes operation of the main switch.

5. Automatic switching mechanism including in combination a main switchand motor actuating means therefor, a switch in the motor circuit anddriven thereby, a second motor switchpa temperature controlled switch, atime switch, means for disconnecting the temperature controlled switchand time switch immediately after they have operated and means forcontinuing the current supply to the motor until it has .completed itsswitching operation.

6. Automatic switching mechanism including in combination a main switchand motor actuating means therefor, a time switch in the motor circuitpreventing closure of the main switch, during predetermined periods; atemperature controlled switch operative to open and close the mainswitch in accordance with temperature changes subject to control of thetime switch, means for interrupting the flow of current through the timeand temperature controlled switches immediately after one of theirswitching operations and means rendered operative by such interruptionto continue supply of current to the motor until completion of theswitching operation.

7. Automatic switching mechanism including in combination a main switchand motor actuating means therefor, a time switch in the motor circuitpreventing closure of the main switch during predetermined periods, atemperaturecontrolled switch operative to open and close the main switchin accordance with temperature changes subject to control of the timeswitch and means for interrupting the flow of current through the timeand temperature controlled switches immediately after one of theirswitching operations.

8. Automatic switching mechanism including in combination a main switch,electric motor means for actuating the switch, two double throw switchesin the motor circuit, one having its movable member moved from oneposition to the other by operation of the motor to complete a mainswitching operation, a second motor for moving the movable member of thesecond switch between its two positions and a time switch and atemperature controlled switch in series with said second motor.

9. Automatic switching mechanism including in combination a main switch,electric motor means for actuating the switch, two double throw switchesin the motor circuit, one having its movable member moved from oneposition to the other by operation of the motor to complete a mainswitching operation, a second motor for moving the movable member of thesecond switch between its two positions, a time controlled double throwswitch and a temperature controlled double throw switch both in circuitwith said second motor and operative to energize the second motormomentarily to cause said second switch to be operated when an actuationof the main switch is called for by the temperature betweenpredetermined periods of time.

10. Automatic switching mechanism including in combination a mainswitch, electric 'motor means for actuating the switch, two double throwswitches in the motor circuit, one having its movable member moved fromone position to the other.

by operation of the motor to complete a main switching operation, asecond motor for moving the movable member of the second switch betweenits two positions, a pair of switches in circuit with said second motorand adapted to be intermittently actuated independently of each other,said switches being so connected in the motor circuit that one causesmotors to be energized only while the other of said last mentionedswitches is in one of its positions while said other switch affects themotor circuits only when'the main switch is closed.

ALBERT WULLSCHLEGER.

